Kgio 2.7.3 - kinder, gentler non-blocking I/O

kgio provides non-blocking I/O methods for Ruby without raising
exceptions on EAGAIN and EINPROGRESS. It is intended for use with the
Unicorn and Rainbows! Rack servers, but may be used by other
applications (that run on Unix-like platforms).

Changes:

kgio 2.7.3 - compatibility fixes

Fixed build and autopush support under Debian GNU/kFreeBSD.
Test case fixes for timing-sensitive tests.